 Sickle cell anemia is an inherited disorder that affects the red blood cells. Because it is inherited, it means that it can be passed from parent to child. So what is it? Red blood cells contain red protein called hemoglobin, which carries oxygen around the body. Normally red blood cells are round and flexible, which means they can bend to move easily through the narrow blood vessels. People with sickle cell anemia have a change or mutation in the hemoglobin gene. This faulty version of the gene causes the hemoglobin to form strands in the red blood cells, which makes them inflexible and gives them a crescent or a sickle shape. This is where the name of the disorder comes from. A sickle is a tool used to cut long grass. These unusually shaped red blood vessels can cause blockages in sections of the blood vessels. Red blood cells cannot pass through the blockages to reach the cells in tissues and organs, so the cells cannot get oxygen and glucose for respiration. When this happens, it causes pain called a sickle cell crisis. The symptoms of a crisis can be severe and last from a few minutes to several weeks. It can cause complications which can be life-threatening. For example, if a blockage occurs in the blood vessels in the brain, then brain cells can die, which causes a stroke. So how is sickle cell anemia inherited? To have the disorder, you have to have two copies of the faulty allele, which is a recessive allele. People who have one copy of the recessive allele are carriers. The red blood cells of carriers have 50% abnormal hemoglobin and are slightly more fragile than normal. If these two sickle cell carrier parents have offspring, they can have children with the disorder, children who are also carriers or children who are completely unaffected, which we can show in a Punnett square. There are about 4.4 million people in the world who have sickle cell anemia, while an additional 43 million are carriers. About 80% of people with sickle cell anemia live in Central Africa. It also occurs relatively frequently in parts of India, the Middle East and among people of African origin living in other parts of the world. These regions are also most affected by the disease malaria. This is not a coincidence. Having the sickle cell allele actually protects you against malaria. This means you are more likely to survive childhood and pass on the sickle cell allele to your children. This also means that the numbers suffering from sickle cell anemia are also higher in malaria regions. Because if two carriers have children, they have an increased risk of having children with the disorder. But how does carrying the sickle cell allele help protect against malaria? The malaria parasite is transmitted by female mosquitoes, which spend part of its life cycle inside red blood cells. When these parasites enter the fragile red blood cells of carriers, the cells often burst before the parasite has time to develop. This means the parasite dies and the life cycle is broken. So, in this video you have learnt what sickle cell anemia is, how it is inherited and why it is more common in some areas of the world than others. If you liked the video, give it a thumbs up and don't forget to subscribe. Comment below if you have any questions. Why not check out our Fusco app as well. Until next time.